The invention relates to an integrated circuit having a lateral transistor comprising emitter and collector regions of a first conductivity type laterally spaced apart and extending from the surface of a region of a second conductivity type opposite to the first type, the lateral space of said region of the second type situated between the emitter and collector regions forming the base of the transistor and comprising electrical emitter and collector connections, each of which has at least one zone in electrical contact through windows of an insulating layer with the emitter region and with the said collector region, respectively, the emitter region having a depth and a doping level such that the diffusion length of the minority charge carriers vertically injected into the latter region in greater than or equal to the thickness of the said region, while the ratio between the surface of the said emitter region and that of the said electrical connection emitter zone is at least equal to 20.
Such a circuit has been described in European Patent Application No. 228-748 entitled "Procede de fabrication d'un transistor lateral integre et circuit integre le comprenant".
The lateral transistor of the kind described in this prior art document has an amplification improved by a factor that can reach about 1.4 with respect to the lateral transistors manufactured previously.
Thus, lateral transistors can be obtained, whose current amplification is of the order of 10.
However, one of the crucial problems met in lateral transistors is that their current amplification remains much lower than the current amplification of vertical transistors, which may be of the order of 50 to 100.